RAPID EXTRACTION AND STRUCTURAL CHARACTERIZATION OF BIOMOLECULES IN AGAROSE GELS BY LASER DESORPTION FOURIER-TRANSFORM MASS-SPECTROMETRY

A method originally developed for the extraction of biomolecules from agarose gel slices has been utilized as a rapid means of isolating bio logical compounds from gels for subsequent structural characterization by matrix-assisted laser desorption-ionization Fourier transform mass spectrometry (MALDI/FTMS). This''freeze-squeeze'' extraction method i nvolves pressure extrusion of fluid from frozen gel slices and provide s near 50% recovery of analyte in less than 5 min. Experiments were di rected at examining the recovery efficiency of the extraction method u sing C-14-labeled adenosine monophosphate and investigating the effect of high buffer concentrations on the laser desorption mass spectra. W hen coupled with this extraction technique, MALDI/FTMS can be used to detect and identify biomolecules at the low picomole level in agarose gel slices. The accurate mass measurements and MS/MS capabilities of t he FTMS were exploited to provide detailed structural information at t he isomeric level for oligonucleotides electrophoresed into agarose ge ls.